Comparative tracking error analysis of five different optical tracking systems

TLDR

Optical tracking systems for image‑based surgical guidance require optimal placement of the dynamic reference frame relative to the camera. This study investigates the precision of the optical tracking system component, rather than overall navigation accuracy. The authors quantified OTS precision by measuring jitter across five camera‑DRF configurations using FlashPoint and Polaris systems on a linear test rig. FlashPoint and Polaris achieved RMS jitter below 0.11 mm, with FlashPoint ranging 0.028–0.059 mm and Polaris 0.058–0.115 mm, and error distributions differed, especially with the component directed away from the camera dominating total jitter. Total jitter is dominated by the component measured along the axis directed away from the camera.

Abstract

AbstractObjective: Effective utilization of an optical tracking system for image-based surgical guidance requires optimal placement of the dynamic reference frame (DRF) with respect to the tracking camera. Unlike other studies that measure the overall accuracy of a particular navigation system, this study investigates the precision of one component of the navigation system: the optical tracking system (OTS). The precision of OTS measurements is quantified asjitter. By measuring jitter, one can better understand how system inaccuracies depend on the position of the DRF with respect to the camera.Materials and Methods: Both FlashPoint™ (Image Guided Technologies, Inc., Boulder, Colorado) and Polaris™ (Northern Digital Inc., Ontario, Canada) optical tracking systems were tested in five different camera and DRF configurations. A linear testing apparatus with a software interface was designed to facilitate data collection. Jitter measurements were collected over a single quadrant within the camera viewing volume, as symmetry was assumed about the horizontal and vertical axes.Results: Excluding the highest 5% of jitter, the FlashPoint cameras had an RMS jitter range of 0.028 ± 0.012 mm for the 300 mm model, 0.051 ± 0.038 mm for the 580 mm model, and 0.059 ± 0.047 mm for the 1 m model. The Polaris camera had an RMS jitter range of 0.058 ± 0.037 mm with an active DRF and 0.115 ± 0.075 mm with a passive DRF. Conclusion: Both FlashPoint and Polaris have jitter less than 0.11 mm, although the error distributions differ significantly. Total jitter for all systems is dominated by the component measured in the axis directed away from the camera.Key Words: optical tracking systemtracking accuracyimage-guided surgerystereotactic surgery